Clean up DOM renderer code for untested minor performance advantages

src/ol/renderer/dom/domtilelayerrenderer.js

@@ -70,26 +70,19 @@ ol.renderer.dom.TileLayer.prototype.getTileLayer = function() {
 ol.renderer.dom.TileLayer.prototype.renderFrame =
     function(frameState, layerState) {
 
-  var view2DState = frameState.view2DState;
-
-  var tileLayer = this.getTileLayer();
-
   if (!layerState.visible) {
     if (this.renderedVisible_) {
       goog.style.showElement(this.target, false);
       this.renderedVisible_ = false;
     }
-    return false;
+    return;
-  }
-
-  if (layerState.opacity != this.renderedOpacity_) {
-    goog.style.setOpacity(this.target, layerState.opacity);
-    this.renderedOpacity_ = layerState.opacity;
   }
 
+  var tileLayer = this.getTileLayer();
   var tileSource = tileLayer.getTileSource();
   var tileGrid = tileSource.getTileGrid();
 
+  var view2DState = frameState.view2DState;
   var z = tileGrid.getZForResolution(view2DState.resolution);
 
   /** @type {Object.<number, Object.<string, ol.Tile>>} */
@@ -219,6 +212,11 @@ ol.renderer.dom.TileLayer.prototype.renderFrame =
     }
   }
 
+  if (layerState.opacity != this.renderedOpacity_) {
+    goog.style.setOpacity(this.target, layerState.opacity);
+    this.renderedOpacity_ = layerState.opacity;
+  }
+
   if (layerState.visible && !this.renderedVisible_) {
     goog.style.showElement(this.target, true);
     this.renderedVisible_ = true;